The present invention relates to a load setting device having a control element (11) which can act on a setting member (16) which determines the power of an internal combustion engine, the control element being connected to a driver (4) coupled to an accelerator pedal (1) and being furthermore movable by means of an electric servomotor (9), having a desired-value detection element (7) associated with said driver (4), an actual-value detection element (12) which cooperates with said desired-value detection element (7) and acts on the electric actuator (9), the actuator (9) being adapted to be controlled as a function of the detected values by an electronic control device (22).
Load setting devices of this type are provided in automotive vehicles for actuating the throttle valve or the injection pump by means of the accelerator pedal, so as to be able to intervene by means of the electronic control device in such a manner that, for instance, wheel spinning upon starting as a result of excessive power is avoided. The control device can see to it that, for instance, upon too rapid a depressing of the accelerator pedal, the throttle valve is opened less than corresponds to the position of the accelerator pedal, so that the internal combustion engine produces only an output which does not lead to the spinning of the wheels. Other automatic interventions of the load setting device are necessary if a gear is to be shifted automatically or if the idling speed of rotation is to be brought to a constant value even in the case of different requirements as to power upon idling It is also known in the case of such a setting device to intervene by means of a speed-limiting controller which, by the possibility of disengaging the control element from the accelerator pedal, can see to it in each case that that power is set which is necessary in order to maintain the speed which has been set. In addition, it may be desirable from the standpoint of driving comfort to provide a progressive or degressive coupling of the accelerator pedal with the possibility of a power setting which is reduced or increased compared to the accelerator position
Considerations of safety make it necessary, however, that upon release of the position of the accelerator pedal, there is assurance, even in the event of a defect in the control device, that the power set decreases synchronously with the position of the accelerator pedal. This has been achieved up to now by safety devices in the electronic control device. Possibilities of error in the control electronics are reduced by building the electronic system in redundant fashion. Nevertheless, too high a power setting which is not in accord with the position of the accelerator pedal cannot be completely excluded in the event of a defect.
Load setting devices of the aforementioned type are generally developed of a plurality of parts, i.e. certain elements are associated with the accelerator pedal while other elements cooperate with the control element Such a separate arrangement of the component parts results, on the one hand, in an increased size of the load setting device while, on the other hand, due to the arrangement of the parts at different places of the vehicle, assurance is not provided that the parts cooperate, without retroactive effect, with the throttle valve or the injection pump.